Clutch control device for motor vehicles



Aug. 4, 1936. I E. s. HILL ETAL 2,049,737

CLUTCH CONTROL DEVICE FOR MOTOR VEHICLES Filed Jan. 19, 1932 '2 Sheets-Sheet 1 /Z6 /Z6 g5 69 w 9 /23 66 a9 5; v 97 K4 /9 96 18 95 fl i i:

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Aug; 1936- E. s. HILL :1- AL CLUTCH CONTROL DEVICE FOR MOTOR VEHICLES 2 Sheets-Sheet 2 Filed Jan. 19, 1932 Patented Au 4, 1936- PATENT OFFICE CLUTCH CONTROL DEVICE FOR MOTOR VEHICLES Edward G. Hill and Henry W. Hey, Richmond,

Va., assignors to Hill Engineering Corporation,

Richmond, Va.,-a corporation of Virginia Application January 19, 1932, Serial No. 587,578

24 Claims.

This invention relates to clutch control deviceswe have described and claimed a clutch operating device for motor vehicles which constituted an improvement over the devices disclosed in the copending application of Edward G. Hill, Serial Nos. 487,319, filed October 8th, 1930, and 537,155, filed May 13th, 1931. In each of the copending applications referred to there is disclosed a power mechanism particularly adapted for iise in operating and controlling the clutch of a motor vehicle. In these prior constructions, the power mechanism preferably is in the form of a differential pressure operated power device which is operable from any suitable source of differential pressure such as the vacuum of the intake manifold of a motor vehicle engine.

In each of the prior mechanisms, the power device is operable for disengaging the clutch elements andsubsequentlycontrolling their return movement to operative engagement in such a manner as to provide relatively rapid movement of the clutch elements to a point whereengagement of the clutch elements is about to take place, and then retarding further movement to prevent grabbing of the clutch elements.

The present invention is an improvement over the prior structures referred to and is principally concerned with the automatic retarding or arresting of the clutch elements as they are about to come into engagement with each other as the clutch elements are being returned to normal engaging position. The means employed for this purpose in the prior constructions referred to have been found to be completely operative and practicable, but their proper operation is dependent upon fairly accurate adjustment of the parts, and upon readjustment as the elements of the clutch become worn, or as readjustment of the clutch elements are required for any reason.

An important object of the present invention is to provide automatic means operable in conjunction with aclutch operating device for arresting or retarding the movement of the clutch,

elementsv as they are. about to come into operative engagement with each other.

A further object is to provide an apparatus of the character referred to wherein fine accuracy of adjustment is unnecessary and wherein perfect operation takes place indefinitely regardless of the adjustment of the clutch elements.

A further object is to provide novel means which is automatically operative for arresting the movement of the clutch elements toward operative position in engagement with each other and which depends for its operation on the effect produced as the clutch elements initially contact with each other prior to the time at which such contact becomes operative for propelling the vehicle.

A further object is to provide an apparatus of the character referred towhich is particularly adapted for use in connection with a differential pressure operated clutch control device and wherein the change in differential pressure in 10 the power device which takes place-when the clutch elements come into initial engagement is utilized for arresting the movement of the clutch elements at such point to permit the full return of the clutch elements into operative engagement 15 to be smoothly and accurately controlled.

A further object is to provide an apparatus of the character just referred to in combination with novel means controlled by the degree of suction of the intake manifold for determining the rate of movement of the clutch elements into operative engagement.

Other objects and advantages of the invention will become apparent during the course of the following description.

In the drawings we have shown one embodiment of the invention. In this showing,

Figure l is a side elevation of-the apparatus and parts of the vehicle mechanism to which it is attached, portions of the vehicle being shown in section,

Figure 2 is a vertical sectional view taken axially through the-power device and the main control valve associated therewith, I

Figure 3 is an enlarged sectional view on line 3-3 of Figure 1,

Figure 4 is a section on line 4-4 of Figure 3 with the valve chest removed, and,

Figure 5 is a detail plan view of the treadle rock shaft.

Referring to Figure l, the numeral l0 designates the engine of a motor vehicle having the usual intake manifold II and exhaust manifold I2. The motor is provided with the usual clutch indicated as a whole by the numeral l3, and the control shaft 14 of the clutch extends fromthe casing thereof to be operated by a pedal I5 which may be conventional in construction, as shown. The upper end of the pedal l5 extends through the usual opening in a sloping floor board I 6 connected at its upper end to the dash ll of the vehicle.

The differential pressure power device is illustrated in Figure 2 and is designated as a whole by the numeral Hi. The power device comprises upper and lower casing sections I9 and 20 having parallel adjacent annular flanges 2| which receive therebetween the annular edge portion of a diaphragm 22. The flanges 2! are secured tightly against the edge of the diaphragm by bolts 23 or other suitable fastening elements.

Disks 24 are secured by rivets 25 against opposite faces of the fiat bottom of the casing sec tion 29. Outwardly of the disks 24, the lower casing section is provided with vent openings 26 opened tothe atmosphere. A cup 21 is arranged against the lower disk 24 and is secured thereto by the rivets 25 in spaced relation to the bottom of the casing section 20. Brackets 28 and 29 are adapted to secure the power device to the dash l1. The upper bracket 28 is secured against the top of the upper casing section I9 by rivets 30, while the lower bracket 29 is secured to the cup 21 by bolts 3|. These bolts also operate to secure a bearing 32 against the bottom of the bracket 29.

The bearing 32 slidably receives a rod or shaft 33, and suitable openings are provided through the disks 24, the bottom of the lower casing section 20, the cup 21 and bracket 29, for the passage of the shaft 33 therethrough. The upper end of the shaft 33 is reduced as at 34, and thereduced end of the shaft passes through suitable openings formed in the center of the diaphragm 22 and in the center of disks 35 arranged against opposite sides of the diaphragm. The shoulder formed by the reduced end 34 of the shaft engages against the bottom disk 35, while a nut 36 is threaded on the upper end of the reduced end of the shaft and engages the upper disk 35. It will be apparent therefore that the shaft is fixed with respect to the diaphragm 22 to move upwardly and downwardly therewith in a manner .to be described.

An expansible and contractible sleeve 31 surrounds the lower portion of the shaft 33 and has its upper end connected to and surrounding the lower end of the bearing 32, as shown in' Figure 2. The lower end of the sleeve 31 is connected to the shaft 33 at a point spaced a substantial distance beneath the bearing 32. The sleeve may be made of rubber or similar flexible material and operates to protect the shaft 33 against dirt or other foreign material, but permits free vertical movement of the shaft.

The lower end of the shaft 33, just below the sleeve 31, is pivotally connected as at 38 to a yoke 39 connected to one end of a flexible cable 40. This cable passes around a pulley 4| journalled in a suitable bearing bracket 42 mounted upon any stationary part of the vehicle, as will be apparent. The other end of the cable 49 is provided with a yoke 43 pivotally connected as at 44 to the clutch pedal l5. It will be apparent that upward movement of the shaft 33 exerts an upward pull on the adjacent end of the cable 40, which movement is transmitted to the opposite end of the cable to move the clutch pedal I5 downwardly to inoperative position.

Referring to Figures 2 and 3 the numeral 45 designates a valve chest as a whole divided by a central wall 46 to form valve chambers 41 and 48. A valve indicated as a whole by the numeral 49 is vertically movable in the chamber 41 and comprises upper and lower heads 50 and 5! connected by areduced shank.52. The upper end of the chamber 41 is capped as at 53 and a vent opening 54 is provided in the capto prevent variation in pressure above the valve 43. The lower end of the chamber 41 is provided with a head 55 through which a stem 56 is axially slidable, and the upper end of this stem is secured to the valve head 5|. The lower end of the chamber 41 is vented to the atmosphere as at 51.

Any suitable means may be employed for operating the valve stem 56 to move the valve 50 to its upper and lower positions. One form of mechanism for operating the valve stem 56 is illustrated in the drawings. Referring to Figure I, the numeral 58 designates a bracket secured against one side of the bearing 32 and provided with outstanding arms 59 rotatably supporting a rod 60. A spring 6| is connected between this rod and the bracket 58 in any suitable manner to tend to rotate the rod in one direction to maintain the valve 49 in its lower normal position shown in Figure 3, in a manner to be described. One end of the rod 60 is provided with an arm 62 pivotally connected as at 63 to one end of a link 64 and the upper end of this link is pivotally connected as at 65 to the lower end of the valve steam 56 The other end of the rod 66 is provided with an arm 66. The end of this arm is universally connected, as by means of a ball and socket joint 61, to the upper end of a link 68. The lower end of this link is similarly connected by a ball and socket joint 69 to an arm 10 carried by a rock shaft 1|. The ball of the connection 69 is shown in Figure 5 and is designated by the numeral 12. The rock shaft 1| is journalled at one end in a suitable opening 13 drilled through the dash l1, while the rock shaft is journalled adjacent its opposite end in a bearing 14 connected by a suitable swivel means to a plate 15 secured against the floor board l6. The purpose of the swivel mounting of the bearing 14 is to permit the installation of the rock shaft 1| at different angles, which is necessary with installations on different makes of motor vehicles.

An accelerator rod 16 extends through the floor board l6 and is provided with the usual button 11 at its upper end. If the vehicle to which the device is to be applied is provided with an accelerator treadle in place of the button 11, the treadle may be removed and one of the buttons 11 threaded on the upper end of the accelerator rod 16. The lower end of the rod 16 is connected to one end of a pivoted lever 11, and the other end of this lever is connected to one end of aconventio-nal throttle rod 18 leading to the throttle valve of the carburetor.

An operating treadle 19 is arranged as shown in Figure 1 with its forward end resting upon the button 11. A hinge member is pivotally connected at its rear end to the lower end of the treadle as at 8|, the other end of the hinge member being pivotally connected as at 82 to the plate 15. It will be apparent that the lower end of the treadle is adapted to be depressed regardless of the positions of the upper end of the treadle and the accelerator button 11. The lower end of the treadle is in operative engagement with a substantially spherical roller 83 carried by a crank arm 84 preferably formed integral with and offset from the lower end of the rock shaft 1|. From the foregoing it will be apparent that depression of the lower end of the treadle 19, operating against the roller 83,

rccksfthe shaft 1| about its axis.

As previously stated, the valve 50 normally occupies its lowermost position, as shown in Figures 2 and 3. The valve chest is provided with a port 85 communicating with the valve chamber 41 just below the head 50 when the municates with one end of a conduit 86, as shown in Figure 2. The other end of the conduit 86 is connected to the branch of a T 81, and the lower end of the run of the T is connected tothe upper casing section I9 to communicate with the interior thereof. The upper end of the run of the T 81 is preferably reduced as at 88 and is connected by a union 89 to a pipe 99, for a purpose to be described. Above and preferably opposite the port 85, the valve chamber 41 is provided with a port 9| normally closed by the valve head 59 and adapted to be opened when the valve is moved to upper position. One end of the run of a T 92 is connected to the valve chest in communication with the port 9 I. The'branch of the T 92 communicates with one end of a conduit 93, and the opposite end of this conduit is connected as at 94 to the intake manifold II. The outer end of the runof the T 92 is preferably reduced as at 95 and is connected by a union 96 to one end of a pipe 91 for a purpose to be described. It will be apparent that the TS 81 and 92' may be exact duplicates of each other.

Referring to Figure 2, the numeral 99 designates a diaphragm housing as a whole compris-1 ing sections 99 and I99 having annular flanges between which the edge portion of a diaphragm ml is secured by bolts I92. A valve stem I93 has one end connected to the diaphragm IM and is provided at its opposite end with a valve I94 adapted to engage against a seat I95. This valve seat communicates with the chamber 41 through a port I96. 7 The diaphragm |9| forms with the housing section I99 a. chamber I96 which communicates with the atmosphere through a vent port I91.

' The housing section 99 is provided with an integral hollow extension I98 in which is arranged a spring I99, and this spring acts to move the diaphragm IIiI in one direction to tend to open the valve I94. A screw 9 is adapted to adjust the tension of the spring I99 to determine the differential pressure necessary to hold the valve I94 in closed position, as will become apparent. The diaphragm |9I forms with the housing 99 a suction chamber III which is connected to the other end of the pipe 91 by means of a union II2. It will be apparent that the chamber III is always in communication with the intake manifold through pipe 91, T 92 and conduit 93-, while the port I91 is always in communication with the atmosphere. During the normal operation of a vehicle engine therefore, differential pressure is present on opposite sides of the diaphragm I9| tending to maintain the valve I94 in closed positlon The valve I94 and its operatingmeans per se are described and claimed in our copending application Serial No. 578,394, referred to above.

' The wall 46 dividing the valve chambers 41 and 48 is provided with a port I I3 affording communication under certain conditions between the chambers 41 and 48. The outer wall of the latter chamber is provided with a port I I4 arranged in alinement with the port 3 and communicating withthe atmosphere. A valve 5 is slidable in the chamber 48 and is provided with an annular groove 6 affording, communication between the ports H3 and H4 when the valve I I5 is in the normal position shown in Figure 3. The lower end of the chamber 48 may be provided with a cap I" vented to the atmosphere .asatIIB.

. ing section I29 is provided with a hollow axial other hand, it will be apparent'that the throttle A diaphragm housing indicated as a whole by the numeral 9 comprises sections I29 and |2I having annular flanges between which a diaphragm I22 is secured by bolts I23. The housing section I2| is provided with a hollow-axial 5 extension I24 threaded in the upper end of the valve chamber 48. A valve stem I25 is connected at its lower end to the valve 5 and at its upper end to the diaphragm I22. The housextension I26 in which the upper end of a spring I21 is arranged. The lower end of this spring operates against the diaphragm I22 tending to move the latter to its lower limit of movement whereby the valve I I5 tends to move to the normal position shown in Figure 3. A screw I28 adjusts the tension of the spring I21 and determines the degree of differential pressure on opposite sides of the diaphragm I22 necessary to operate this element.

The diaphragm I22 forms with the housing see- I tion I2| a chamber I 29 communicating with the atmosphere through a port I39. In a similar manner, the diaphragm forms with the upper housing section I29 a chamber I3| communicat- 25 ing with a port I32 formed in'a boss I33 carried by and extending from the housing section I29. As previously stated, one end of the pipe 99 is connected to the reduced upper end of the run of the T- 81 and the other end of the pipe 99 is 30 connected to the boss I33 by a union I34. The operation of the apparatus is as follows:

It will be apparent that the shaft 1| may be rocked by depression of the lower end of the treadle 19, and this action may take place re gardless of the throttle position since the hinged connection for the lower end of the treadle permits depression thereof regardless of the position of the upper ehd of the treadle. On the 40 may be operated through its entire range of movement by operation of the upper end of the treadle without affecting the clutch since the upper end of the treadle is freely movable without depress,- ing the lower end of the treadle.

When it is desired to release the clutch elements, the rear end of the treadle is depressed, preferably simultaneously with the releasing of the upper end of the treadle to permit the engine to idle. Depression of the lower end of the treadle moves the roller 83 and crank arm 84 downwardly, thus rocking the shaft 1| and moving the arm 19 of the shaft downwardly. This action in turn exerts a downward pull upon the link 68, thus moving the arm 66 of the rod 69 downwardly, whereupon the rod 69 will rock about its axis against the tension of the spring 6|. The rocking movement of the rod 69 causes the arm 62 to swing upwardly, and this movement is transmitted through the link 64 and stem 56 to the 60 valve 49, and thus the valve will be moved to its upper limit of movement.

When the valve is thus moved to its upper or operative position, the upper head 59 uncovers the port 9|; while the lower valve head 5| covers 65 the port I96. Under such conditions, the ports 85 and 9| will communicate with each other around the valve shank 52, and accordingly the ,upper casing section I9 of the power device will 22 will effect upward movement of the diaphragm and shaft 33, whereupon a pull will be exerted upon the cable 40 to move the clutch pedal I downwardly and completely disengage the clutch elements. While the cable 40 is shown as being connected to a standard clutch pedal I5, it will be apparent that any suitable connection may be made to release the clutch elements upon operation of the power device.

It will be apparent that the chamber I3I (see Figure 4) is always in communication with some portion of the vacuum space defined by the conduit 86 and T 81 and the space above the diaphragm 22. The pipe 90 provided for this purpose is shown connected to the upper end of the T 81, but it will be apparent that it readily may be connected to the conduit 86 or the interior of the upper casing section I9. Accordingly it will be apparent that when the air in the upper casing section I9 is evacuated upon the operation of the valve 49, the air also is exhausted from the pipe 90 and the chamber I3I, whereupon atmospheric pressure beneath the diaphragm I22 moves the diaphragm upwardly against the tension of the spring I 21, thus moving the valve I I5 to its upper limit of movement at which point both of the ports I I3 and II 4 are uncovered. At this time, however, air cannot flow through the ports referred to into the valve chamber 41 since the inner end of the port H3 will be covered by the valve head 5|.

From the foregoing it will be apparent that upward movement of the valve 49 by depression of the lower end of the treadle 19 effects movement of the clutch elements to released position, and accordingly the operator is free to shift gears without operating the clutch pedal. Assuming that the operation previously described has taken place with the vehicle at rest and with the gear shift lever in neutral position, the operator will place the gear shift lever in low gear position, whereupon it merely is necessary to release the lower end of the treadle 19 and depress the forward end thereof. As is well known, it is desirable to permit the clutch elements to come into engagement more slowlywhen the vehicle is in low gear than when it is in second or high gears, and this operation takes place automatically in a manner to be described upon the depression of the upper end of the treadle 19.

When the lower end of the treadle is released after the gear shift lever has been placed in low gear position, the spring GI operates to return the parts connected thereto to normal position, the valve 49 moving downwardly to'the position illustrated in Figures 2 and 3. At such time, it will be apparent that the vacuum port 9| again will be covered by the valve head 50 'while the port H3 will be uncovered by downward movement of the valve head 5|. As previously stated, the valve II5 moves upwardly when corresponding movement of the diaphragm 22 takes place, and accordingly the space in the valve chamber 41 surrounding the shank 52 will be connected to the atmosphere through ports H3 and H4 the instant the valve head 5I passes downwardly beyond the port II3. Under such conditions, air will rush through ports I I 4 and I I3 into the valve chamber 41 around the shank 52, and then into the upper casing section I9 through port 85, conduit 86 and T 81.

The movement of air in the manner referred to immediately reduces the pressure differential on opposite sides of the diaphragm 22, whereupon the diaphragm is promptly caused to move downwardly by the action of the usual clutch springs (not shown). It. also will be apparent that the building up of pressure to some extent in the power device through the passage of air in the manner described also affects the operation of the diaphragm I22, the pressure above this diaphragm preferably being built up toa sufiicient extent to reduce the pressure differential on op posite sides of the diaphragm to permit the spring I21 to move the diaphragm downwardly sufficiently to cause the valve II5 to partially close the ports I I3 and I I4 and thus reduce their effective area for permitting air to flow to the upper casing section I9.

The operation referred to obviously reduces the vacuum in the upper casing section I9 below the point necessary for holding the diaphragm 22 against downward movement, and accordingly the clutch springs move the clutch elements toward operative engagement and such movement is transmitted to the diaphragm 22 to move it downwardly. The fiow of air in the manner referred to above is restricted in accordance with the ports I I3 and I I4, and in practice the flow of air is insufficient to satisfy the vacuum existing in the upper casing section I9. In this connection, it is pointed out that the pressure built up in the casing section I9 will be dependent upon three conditions, namely the area of the diaphragm 22, the tension of the clutch springs tending to move the .diphragm downwardly, and the effective area of the ports H3 and I I4. The tension of the spring I21 is readily adjustable by operating the screw I28 to secure proper operation of the diaphragm I22 under the correct conditions of differential pressure whereby the valve I5 moves downwardly to the intermediate position previously referred to wherein the ports H3 'and H4 are partially closed. At such point, the differential pressure still existing on opposite sides of the diaphragm 22 by virtue of the relatively rapid downward movement of this diaphragm is sufficient to prevent further downward movement of the diaphragm I22 and its associated valve H5, and accordingly the ports H4 and H3 will remain partially open to permit air to continue to flow into the casing section I9.

Further downward movement of the valve II5 will then depend upon the creation of increased pressure in the casing section I9, and such increased pressure is attained substantially at the instant when the clutch plates initially contact. This initial engagement of the clutch plates retards movement of the diaphragm 22 suflicient- 1y to change the ratio between the three conditions referred to above, namely the areaof the diaphragm 22, the rate of downward movement of this diaphragm, and the effective areas of the ports H3 and H4. Under such conditions, the effective areas of the ports H3 and H4 will be suflicient to raise the pressure in the casing section I9 and this increased pressure is communicatedto the diaphragm chamber I3I, thus permitting the spring I21 to move the valve II5 downwardly to fully closed position thus preventing the flow of additional air through the ports H3 and H4.

In this connection it should be noted that the differential pressure existing on opposite sides of the diaphragm 22 as it moves downwardly is only'slightly below the differential pressure necessary to hold this diaphragm stationary, and accordingly a suflicient increase in pressure in the casing section I9 to drop the valve H5 to closed position occurs substantially instantaneously upon initial contact of the clutch plates,

and accordingly movement of the parts will be completely arrested before the clutch plates move into substantial contact with each other. In fact, the degree of engagement of the clutch plates'at the time their movement is arrested is insuflicient to transmit any motion to the vehicle.

The operation thus, .far described covers the complete releasing of the clutch elements, the placing of the gearshift lever in low gear position, and the automatic releasing of the clutch elements to move rapidly to a point at which the clutch elements lightly contact, whereupon it is necessary only to effect slight further movement of the clutch elements to bring them into operative engagement. It will be apparent that the movement of the clutch elements into light contact with each other takes place automatically and very rapidly, and accordingly it will be apparent that the vehicle is ready to proceed practically instantaneously with the releasing of the lower end of the treadle l9.- Afterthis action is performed, it merely is necessary for the operator to depress the upper end of the treadle i9.

As previously stated, it is the common practice in the conventional operation of motor vehicles to permit the clutch elements to move slowly into engagement with each other when in low gear, and at such time the throttle of the vehicle is slowly opened to permit a gradual picking up in the momentum of the vehicle. Accordingly, when the operator depresses the upper end of the treadle '19, he performs this operation relatively slowly and a corresponding relatively slow movement of the clutch elements into engagement with each other takes place, and the latter action is wholly automatic. Upon the depression of the upper end of the treadle 19 in the manner referred to and the corresponding relatively slow movement of the throttle toward open position, the degree of vacuum in the intake manifold is relatively slightly reduced, or in other words, the pressure in the intake manifold slightly increases. This slight increase in manifold pressure is communicated to the diaphragm chamber l H through conduit 93, T 92 and pipe 91.

A slight increase in pressure in the chamber l I I. obviously slightly reduces the pressure differential on opposite sides of the diaphragm HM, whereupon the spring I09 operates to move the diaphragm IM to a slight extent, thus slightly opening the valve I04. Since the chamber I96 communicates with the atmosphere through port I01, it will be apparent that the slight opening of the valve I04 permits a slow movement of air into the valve chamber around the shank 52, and this air flows into the upper portion of the power device through pipe 86 and T 81. The pressure differential on opposite sides of the diaphragm 22 accordingly is slowly reduced, and the diaphragm moves downwardly to permit the clutch elements to come into engagement relatively slowly. The operator continues to depress the upper end of the treadle l9 until the vehicle has attained sufficient momentum whereupon the lower end of the treadle is depressed and the upper end released, preferably simultaneously whereupon the clutch again will become disengaged and the vehicle is ready to be placed in second gear. It will be apparent that the continued feeding of air into the upper end of the power device to complete the engagement of the clutch elements establishes pressure equalization in the upper chamber of the power device and consequently in the chamber l3l. Accordingly the diaphragm I22 moves to its lower limit together with the valve H5, and the groove H6 communicates between the ports H3 and l M to normally connect the power device to the atmosphere and prevent .danger of upward creeping of the diaphragm 22.

The operation of the device when the vehicle is in second gear is substantially identical with that previously described and need not be referred to in detail. As is well known, the operator of a motor vehicle may permit somewhat more rapid clutch element engagement in second gear than in low gear due to the momentum of the vehicle, and such increased speed of movement of the clutch elements into engagement under such conditions usually is practiced by the average driver together with a more rapid operation of the accelerator. The present apparatus acts automatically to bring the clutch elements into engagement at a rate corresponding to the rapidity of the opening of the throttle. When the vehicle is in second gear, it merely is necessary for the operator to depress the upper end of the treadle l9 somewhat more rapidly than when in low gear, and this action through the more rapid opening of the throttle decreases the degree of vacuum,

in the manifold to a greater extent. Accordingly the somewhat more rapid increase in the pressure in the intake manifold is communicated to the diaphragm chamber lll, thus more greatly reducing the pressure differential on opposite sides of the diaphragm, whereupon the spring I09 opens the valve IM to a greater extent than when in low gear. This operation in turn permits the more rapid flow of air into the top. of the power device, and more rapid downward movement of the diaphragm takes place together with more rapid movement of the clutch elements into engagement with each other.

The operation is repeated in high gear except that even more rapid clutch engagement takes place, and this condition is taken care of merely by more rapidly depressing the upper end of the treadle 19'. Such action obviously opens the valve I04 to an even greater extent than in the case previously described, and the clutch elements accordingly will move relatively rapidly into operative engagement.

From the foregoing description it will be apparent that the present apparatus provides novel means for operating and controlling the clutch of a motor vehicle without the necessity of having to operate the clutch pedal in accordance with conventional practice. The movement of the clutch to inoperative position and the return of the clutch elements to a point where they lightly contact with each other, is controlled wholly by the movement of the lower end of the treadle 19. The movement of the clutch elements into complete engagement is controlled bythe throttle operation. The movement of the clutch elements to inoperative position obviously is wholly independent of the throttle, the latter being movable throughout its complete range of movement without affecting the clutch in any way. In fact, the

' checking movement of a clutch takes place over long periods of time and upon readjustment of the. clutch elements without adjusting any of the parts of the clutch operating means. This is due to the fact that the retarding of movement of the diaphragm 22 at any time during its downward movement will efiect an increase in pressure in the casing section l9 to drop the valve H5 to closed position. Accordingly the adjustment of a vehicle clutch to cause clutch engagement to take place at difierent points in the travel of the clutch pedal will not affect the operation of the present device in any manner. ,This fact is of extreme importance since with prior constructions it was necessary to secure exact adjustment of the clutchoperating means with respect to the point of engagement of the clutch since rough operation and excessive wear of the clutch facings would occur unless such exact adjustments were provided.

While the operation of the device has been described with the valve I IS initially movable downwardly to such a point as to restrict the ports H3 and H4, such operation is desirable only for the purpose of permitting an initial relatively great flow of air into the diaphragm casings to secure rapidity of operation. It will be apparent however, that the ports H3 and I I4 may be of a size corresponding to their effective area upon initial downward movement of the valve H5 in which case it will be apparent that such initial movement of the valve does not partially close or in any way afiect the ports I I3 and H4 until initial contact of the clutch elements takes place to drop the valve 1 l5 to closed position.

It also will be apparent that flexibility 01' the control of the movement of the clutch elements into operative engagement is provided without the necessity of varying the speed of clutch engagement in accordance with gearshift lever position, the rapidity of clutch element engagement being dependent wholly upon the pressure in the intake manifold.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

We claim:

1. Apparatus of the character described comprising a pressure responsive device connected to a motor vehicle clutch and operative for moving the clutch elements out of engagement with each other, means for supplying vacuum to said pressure responsive device to render it operative, means for at least partially releasing the vacuum acting on said pressure responsive device to release the clutch elements for movement toward operative engagement with each other, means rendered operative by initial contact of the clutch elements with each other for arresting the motion of the clutch elements toward operative engagement, and means for releasing the clutch elements for movement into operative engagement after their movement has been arrested by said last named means.

2. Apparatus of the character described comprising a pressure responsive device connected to a motor vehicle clutch, a conduit connected to a source of suction and to said device and operative for connecting said device to the source of suction to move the clutch elements out of engagement with each other, means operative to admit atmospheric pressure to said conduit to release the clutch elements for movement toward operative engagement, said pressure responsive device operating to maintain a partial vacuum in said conduit during movement of the clutch plates toward operative engagement, means actuated by a drop in vacuum in said conduit occurring upon initial contact of the clutch elements for arresting movement of the clutch elements toward operative engagement, and means for releasing the clutch elements for movement into operative engagement after their movement has been arrested by said last named means.

3. Apparatus of the character described comprising a pressure responsive device connected to a motor vehicle clutch, a conduit connected to a source of suction and to said device and operative for connecting said device to the source of suction to move the clutch elements out of en-.

gagement with each other, means operative to admit atmospheric pressure to said conduit to release the clutch elements for movement toward operative engagement, said pressure responsive device operating to maintain a partial vacuum in said conduit during movement of the clutch elements toward operative engagement, a diaphragm actuated valve operable to closed position by a drop in vacuum in said passage occurring upon initial contact of the clutch elements for arresting movement of the clutch elements toward operative engagement, and means for releasing the clutch elements for movement into operative engagement after their movement has been arrested by said last named means.

4. Apparatus of the character described comprising a power device having a casing provided with a pressure responsive member to form a suction chamber, said pressure responsive member being connected to an operating member of a motor vehicle clutch, a valve operable in one position for connecting said chamber to a source of suction to efiect clutch disengagement, said valve being movable to a second position to connect said chamber to the atmosphere and release the clutch elements for movement toward engaged position, an auxiliary valve movable upon initial contact of the clutch elements for closing communication between said chamber and the atmosphere, and means operative for affording communication between said chamber and the atmosphere after said auxiliary valve has moved to closed position.

5. Apparatus of the character described-comprising a power device having a casing provided with a pressure responsive member to form a suction chamber, said pressure responsive member being connected to an operating member of a motor vehicle clutch, a valve operable in one position for connecting said chamber to a source of suction to effect clutch disengagement, said valve being movable to a second position to connect said chamber to the atmosphere and release the clutch elements for movement toward engaged position, an auxiliary valve, means connected to said auxiliary valve and operative by pressure in said suction chamber upon initial contact of the clutch elements for closing communication between said chamber and the atmosphere, and means operative for afiording communication between said chamber and the atmosphere after said auxiliary valve has moved to closed position.

6. Apparatus of the character described comprising a power device having a casing provided with a pressure responsive member to form a suction chamber, said pressure responsive member being connected to an operating member of a motor vehicle clutch, a valve operable in one position for connecting said chamberto a source of suction to efiect clutch disengagement, said valve being movable to a second position to connect said chamber to the atmosphere and release the clutch elements for movement toward engaged position, an auxiliary valve, an expansible chamber device having an operating member connected to said auxiliary valve and responsive to pressure in said suction chamber upon initial contact of the clutch elements for closing communication between said chamber and the atmosphere, and means operative for afiording communication between said suction chamber and the atmosphere aftersaid auxiliary valve has moved to closed position.

7. Apparatus of the character described comprising a power device having a casing provided witha pressure responsive member to form a suction chamber, said pressure responsive member being connected to an operating member of a motor vehicle clutch, a valve operable in one position for connecting said chamberto a source of suction to effect clutch disengagement, said valve being movable to a second position to connect said chamber to the atmosphere and release the clutch elements for movement toward engaged position, an auxiliary valve, a housing, a diaphragm mounted in said housing and connected to said auxiliary valve and operative by pressure in said suc-.

- tion chamber upon initial engagement of the clutch elements for closing communication between said chamber and the atmosphere, and means operative for affording communication between said chamber and the atmosphere after said auxiliary valve has moved to closed position.

' 8. Apparatus of the character described comprising a power device having a casing provided with a pressure responsive member to form a suction chamber, said pressure responsive member 40 being connected to an operating member of a motor vehicle clutch, a valve housing having an atmospheric port, a valve movable to one position in said valve housing to connect said chamber to the atmosphere through said port and movable to a second position to disconnect said chamber from the atmosphere and connect it to a source of suction, an auxiliary valve movable to operative position to close said port, pressure responsive means connected to said auxiliary valve and operable for moving the latter to operative position under the influence of pressure in said chamber upon initial contact of the clutch elements, and

means operative for afiording communication between said suction chamber and the atmosphere after said auxiliary valve has movedto operative position.

9. Apparatus of the character described comprising a power device having a casing provided with a pressure responsive member to form a suction chamber, said pressure responsive member being connected to an operating member of a motor vehicle clutch, a valve housing having an atmospheric port, a valve movable to one position in said valve housing to connect said chamher .to the atmosphere through said port and movable to a second position to disconnect said chamber from the atmosphere and connect it to a source of suction, an auxiliary valve, a pressure responsive device connected to said auxiliary valve and communicating with said chamber to be op- 'erated by suction therein to move said auxiliary- .valve in one direction to a position uncovering said port, resilient means tending to move said auxiliary valve in the opposite direction, said pressure responsive device being operative by said resilient means to move said auxiliary valve to a position closing said port upon initial contact of the clutch elements, and means operative for affording communication between said chamber and the atmosphere after said auxiliary valve has 5 moved to closed position. I

10. Apparatus of the character described comprising a power device having a casing provided with a pressure responsive member to-iorm a suction chamber, said pressure responsive memberlO being connected to an operating member of a motor vehicle clutch, a valve housing having an atmospheric port, avalve movable to one position in said valve housing to connect said chamber to the atmosphere through said port and movable to 15 a second position to disconnect said chamber from the atmosphere and connect it to a source of suction, an auxiliary valve, a diaphragm casing, a diaphragm arranged in said casing and connected to said auxiliary valve, spring means urging said 20, auxiliary valve in one direction, said diaphragm casing communicating with said chamber whereby said diaphragm is moved by suction in said chamber when said first named valve is in'said second position to move said auxiliary valve in 25 the other direction to a position uncovering said port, said resilient means being operative to move said auxiliary valve to an operative position closing said port upon initial contact of the clutch elements, and means operative for'affording com- 30 munication between said suction chamber and the atmosphere after said auxiliary valve has moved to operative position. i v 11. Apparatus of the character described comprising a differential pressure power device having 35 a casing provided with a movable member to form a suction chamber, said movable member being connected to an operating member of a motor vehicle clutch, a conduit adapted to connect the suction chamber to the intake manifold of the 40 motor vehicle engine, a valve controlling said conduit and adapted to assume a position connecting said chamber to the atmosphere, said valve being movable to an operative position to disconnect said chamber from the atmosphere 45 and to open said conduit, means operative upon initial contact of the clutch elements when said valve moves to said first-named position for rendering said valve ineffective for connecting said chamber to the atmosphere whereby movement of 50 the clutch elements will be arrested, and means for afiording comunication between said chamber and the atmosphere after movement of the clutch elements has been arrested for permitting the clutch elements to move into operative engage 5 ment with each other.

12. The combination with a motor vehicle clutch having a normal bias to operative condition with the elements thereof in engagement with each other, of a pressure responsive device con- 0 nected to the clutch and operative for moving the clutch elements out of engagement with each other, means for supplying vacuum to said pressure responsive device to render it operative, means for at least partially releasing the vacuum 65 acting on said pressure responsive device to release the clutch elements for movement toward operative engagement with each other, means rendered operative by initial contact of the clutch elements with each other for arresting the mo- 70 tion of the clutch elements toward operative engagement, and means for releasing the clutch elements for movement into operative engagement after their movement has been arrested by said last named means. 75

13. The combination with a motor vehicle clutch having a normal bias to operative condition with the elements thereof in engagement with each other, of a pressure responsive device connected to an operating member of the clutch, a conduit connected to a source of suction and to said device and operative for connecting said device to the sourceof suction to move the clutch elements out of engagement with each other, means operative to admit atmospheric pressure to said conduit to release the clutch elements for movement toward operative engagement, said pressure responsive device operating to maintain a partial vacuum in said conduit duringmovement of the clutch plates toward operativeengagement, means actuated by a drop in vacuum in said conduit occurring upon initial contact of the clutch elements for arresting movement of the clutch elements toward each other, and means for releasing the clutch elements for movement into operative engagement after their movement has been arrested by said last named means.

14. The combination with a motor, vehicle clutch having a normal bias to operative condition with the elements thereof in engagement with each other, of a conduit connected to a source of suction and to said device and operative for connecting said device to the source of suction to move the clutch elements out of engagement with each other, means operative to admit atmospheric pressureto said conduit to release the clutch elements for movementtoward operative engagement, said pressure responsive device operating to maintain a partial vacuum in said conduit during movement of the clutch elements toward operative engagement, a diaphragm actuated valve operable to closed position by a drop in vacuum in said passage occurring upon initial contact of the clutch elements for arresting movement of the clutch elements toward operative engagement, and means for releasing the clutch elements for movement into operative engagement after their movement has been arrested by said last named means.

15. The combination with a motor vehicle clutch having a normal bias to operative condition with the elements thereof in engagement with each other, of a power device having a casing provided with a pressure responsive member to form a suction chamber, said pressure responsive member being connected to the clutch, a valve operable in one position for connecting said chamber to a source of suction to effect clutch disengagement, said valve being movable to a second position to connect said chamber to the atmosphere and releasethe clutch elements for movement toward engaged position, an auxiliary valve movable upon initial contact of the clutch elements for closing communication between said chamber and the atmosphere, and means operative for afiording communication between said chamber and the atmosphere after said auxiliary valve has moved to closed position.

16. The combination with a motor vehicle clutch having a normal bias to operative condition with the elements thereof in engagement with each other, of a power device having a casing provided with a pressure responsive member to form a suction chamber, said pressure responsive member being connected to an operating member of the clutch, a valve operable in one position for connecting said chamber to a source of suction to effect clutch disengagement, said valve being movable to a second position to connect said chamber to the atmosphere and release the clutch elements for movement toward engaged position, an auxiliary valve, means connected to said auxiliary valve and operative by pressure in said suction chamber upon initial contact of the clutch elements for closing communication between said chamber and the atmosphere, and means operativefor affording communication between said'chamber and the atmosphere after said auxiliary valve has moved to closed position.

17. The combination with a motor vehicle clutch having a normal bias to operative condition with the elements thereof in engagement with each other, of a power device having a casing provided with a pressure responsive member to form a suction chamber, said pressure responsive member being connected to an operating member of the clutch, a valve operable in one position for connecting said chamber to a source of suction to effect clutch disengagement, said valve being movable to a second position to connect said chamber to the atmosphere and release the clutch elements for movement toward engaged position, an auxiliary valve, an 'expansible chamber device having an operating member connected to said auxiliary valve and responsive to pressure in said suction chamber upon initial contact of the clutch elements for closing communication between said chamber and the atmosphere, and means operative for affording communication between said chamber and the atmosphere after said auxiliary valve has moved to closed position.

18. The combination with a motor vehicle clutch having a normal bias to operative condition with the elements thereof in engagement with each other, of a power device having a casing provided with a pressure responsive member to form a suction chamber, said pressure responsive member being connected to an operating member of the vehicle clutch, a valve operable in one position for connecting said chamber to a source of suction to effect clutch disengagement,

said valve being movable to a second position to connect said chamber to the atmosphere and release the clutch elements for movement toward engaged position, an auxiliary valve, a housing, a diaphragm mounted in said housing and connected to said auxiliary valve and operative by pressure in said suction chamber upon initial engagement of the clutch elements for closing communication between said chamber and the atmosphere, and means operative for afiording communication between said chamber and the atmosphere after said auxiliary valve has moved to closed position.

19. The combination with a motor vehicle clutch having a normal bias to operative condition with'the elements thereof in engagement with each other, of a power device having a casing provided with a pressure responsive member to form a suction chamber, said pressure responsive member being connected to an operating member of the vehicle clutch, avalve housing having an atmospheric port, a valve movable to one position in said valve housing to connect said chamber to the atmosphere through said port and movable to a second position to disconnect said chamber from the atmosphere and connect it to a source of suction, an auxiliary valve movable to operative position under the influence of pressure in said chamber upon initial contact of the clutch elements for closing communication to operative position through said port, and means operative for afiording communication between said suction chamber and the atmosphere after said auxiliary valve is moved to operative position.

20. The combination with a motor vehicle clutch having a normal bias to operative condition with the elements thereof in engagement with each other, of a power device having a casing provided with a pressure responsive member to form a suction chamber, said pressure responsive member being connected to an operating member of the vehicle, clutch, a valve housing having an atmospheric port, a valve movable to one position in said valve housing to connect said chamber to the atmosphere through said port and movable to a second position to disconnect said chamber from the atmosphere and connect it to a source of suction,'an auxiliary valve movable to close said port, pressure responsive means connected to said auxiliary valve and operable for moving the latter to operative position under the influence of pressure in said chamber upon initial contact of the clutch elements, and means operative for affording communication between said suction chamber and the atmosphere after said auxiliary valve has moved to operative position.

21. The combination with a motor vehicle clutch having a normal bias to operative condition with the elements thereof in engagement with each other, of a power device having 9, casing provided with a pressure responsive member to form a suction chamber, said pressure responsive member being connected to an operating member of the vehicle clutch, a valve housing having an atmospheric port, a valve movable to one position in said valve housing to connect said chamber to the atmosphere through said port and movable to a second position to disconnect said chamber from the atmosphere and connect it to a source of suction, an auxiliary valve, 9. pressure responsive device connected to said auxiliary valve and communicating with said chamber to be operated by suction therein to move said auxiliary valve in one direction to a position uncovering said port, resilient means tending to move said auxiliary valve in the opposite direction, said pressure responsive device being operative by said resilient means to move said auxiliary valve to a position closing said port upon initial contact of the clutch elements, and means operative for affording communication between said chamber and the atmosphere after said auxiliary valve has moved to closed position.

22. The combination with a motor vehicle clutch having a normal bias to operative condition with the elements thereof in engagement with each other, of a power device having a casing provided with a pressure responsive member to form a suction chamber, said pressure responsive member being connected to an operating member of the vehicle clutch, a valve housing having an atmospheric port, a valve movable to one position in said valve housing to connect said chamber to the atmosphere through said port and movable to a second position to disconnect said chamber from the atmosphere and connect -sure responsive member it to a source of suction, an auxiliary valve, a diaphragm casing, a diaphragm arranged in said casing and connected to said auxiliary valve, spring-means urging said auxiliary valve in one direction, said diaphragm casing communicating with said chamber whereby said diaphragm is moved by suction in said chamber when said first named valve is in said second position to move said auxiliary valve in the other direction to-a position uncovering sad port, said auxiliary 10 means being operative to move said auxiliary valve to an operative position closing said port upon initial contact of the clutch elements, and means operative for affording communication between said suction chamber and the atmosphere after said auxiliary valve has moved to operative position.

'23. The combination with a motor vehicle clutch having a normal bias to operative condition with the elements thereof in engagement with each other, of a differential pressure power device having a casing provided with a movable member to form a suction chamber, said movable member being connected to an operating member of the vehicle clutch, a conduit adapted to connect the suction chamber to the intake manifold of the motor vehicle engine, a valve controlling said conduit and adapted to assume a position connecting said chamber to the atmosphere, said valvebeing movable to an operative position to disconnect said chamber from the atmosphere and to open said conduit, means operative upon initial contact of the clutch elements when said valve moves to said first named position for rendering sai connecting said chamber to the atmosphere whereby movement of the clutch elements will be arrested, and means for afiording communication between said chamber and the atmosphere after movement of the clutch elements has been arrested for permitting the clutch elements to move into operative engagement with each other.

24. In a system of the class described, a clutch having parts movable into and out of clutching engagement with each other, means normally holding said clutch parts in engagement with each other, pressure responsive means for moving said clutch parts out of engagement with each other, means for supplying vacuum to said pressure responsive means to cause the same to move said clutch parts to disengaged position, means for releasing the vacuum acting on said pressure responsive means whereby said first mentioned means moves said clutch parts toward clutching engagement with each other, 5

means for arresting the motion of said clutch parts toward clutching engagement upon partial contact of said clutch parts, and means operative, after the operation of said means arresting the motion of said clutch parts, to progressively con- 60 trol the degree of vacuum acting on said pres- I whereby the degree of pressure between said clutch parts is progressively controlled.

EDWARD G. HILL. HENRY W. HEY.

valve inefiective for 35 

